Assessment of the shear and creep behavior of reinforced thick adhesively bonded joints at various temperatures

This study delves into the mechanical behaviour of thick single-lap adhesive joints, specifically under shear and creep loading conditions. The research emphasizes the impact of incorporating Pine Bark Micro Corks (PBMC) into the adhesive bonds, examining its effects at various temperatures and loading intensities. To evaluate the tensile properties of both standard and reinforced adhesive bulk specimens, a series of tensile tests were meticulously conducted. Additionally, creep tests were performed on both neat and PBMC-reinforced thick adhesive joints to investigate their creep characteristics when subjected to shear loads. The findings revealed that adding just 1% by weight of PBMCs significantly enhanced both creep behaviour and the overall strength of the adhesive joints. Notably, this addition led to a remarkable 76% reduction in creep displacement at room temperature. As the temperature was elevated to 40 °C, a substantial 56% decrease in creep displacement was observed under a loading level of 160 N. This suggests that the introduction of organic microparticles not only bolstered the mechanical properties but also improved the thermal performance of the joints. Further analysis indicated that the creep tests, conducted across three varying load levels, demonstrated a clear trend: as the load levels increased, the creep displacements escalated dramatically. Additionally, the study included a measurement of the shear modulus of the adhesive for both the neat and reinforced specimens, utilizing the thick shear adhesive joints, to provide a comprehensive understanding of the material’s behavior under diverse conditions. Overall, the results underscore the significant benefits that PBMCs impart to the creep and shear performance of thick adhesive joints.